The present disclosure relates to detecting radiation, and more particularly, to centralized detection and monitoring for low-level radioactive material in a number of facilities, such as steelmaking facilities, at the same time.
In production facilities such as those that produce metal products, radioactive material can present a difficulty that can have far reaching impact. For example, radioactive materials can come into a steelmaking process through the scrap that is prominently used in making steel by electric arc furnace (EAF). The charge for making steel in an EAF is typically 50% to 70%, or more, steel scrap collected through junk yards and scrap dealers. The steel scrap is often shredded and transported to a steelmaking facility. The steel scrap has originated from a wide variety of sources including radioactive sources such as medical equipment. There is the potential for radioactive scrap to reach the steel melt and be integrated into the steel product produced if not screened out. The same circumstance is encountered in foundries, aluminum production and other production facilities where recycled metal is utilized. The radioactive material disrupts the production operation while the radioactive material is removed from the furnace, the baghouse, and/or other production facility that may have been contaminated. The introduction of radioactive material also presents the potential for recalls of the product produced by the facility.
In steelmaking, in the past, it has been common practice to detect radioactive contaminates in scrap loads in trucks, railroad cars, barges and other containers delivering scrap to a steelmaking facility. See, e.g., U.S. Pat. Nos. 5,679,956, 5,705,818, and 6,727,506. These systems can also be used in introducing other recycled material to other production facilities (e.g., aluminum production). These radiation monitoring systems detect radioactive material as the scrap load in the truck, railroad car or other vehicle passes adjacent a radiation detector. One problem is that low-level radioactive material buried within the scrap load is difficult to detect even under typical conditions. Certain radioactive materials such as cobalt, cesium, and radium are common materials that potentially could be found in scrap or other recycled material. Further complicating the matter for steelmaking, certain scrap materials such as hot water heaters contain calcium carbonate which may contain radium. In any case, background radiation from naturally occurring radioactive material (NORM) increases the difficulty of detecting low-level radioactive material in scrap and other recycled material. Complicating the matter further for some facilities such as steelmaking and other metal production operations, certain materials used in the production, such as refractories, can contain thorium, radium and similar naturally occurring radioactive material that may be permitted to enter the production facility.
If a load of scrap or other recycled material is determined to contain an undesired radiation source, the load can be rejected incurring additional costs and delay in the delivery of scrap or other recycled material to the production facility. The rejected load can be searched at the production facility to identify and remove the radiation source from the scrap or recycled load, or the load can be returned to the provider. Cost effective detection is therefore sought for the safe and efficient operation of the production facility. With available radiation detecting systems, when radioactive material is detected in a load of scrap or other recycled material in some facilities, a practice may be followed to retest the load by passing the load by the radiation detector up to three times. If the load passes the detection two out of three times, the load may be deemed safe and permitted to enter the production facility.
The effectiveness of current radiation detection systems is dependent on the configuration and detection or alarm levels of the detection system, as well as on the procedures followed by the local radiation safety officer (LRSO) on duty in interpreting detection data. As a result, the radiation detection systems operation may vary with each installation and even with each LRSO on duty at a given installation.
In addition to detection systems used at the railroad portal or truck gates to screen incoming scrap or other recycled material, other radiation detection systems often with varying configurations and different detection levels may be used in the clam shell or conveyer used to load scrap or other material to the furnace ladle or other processing container, in detection of radioactive material in molten samples taken at different points in the production process, and in the detection of radioactive material in bag houses and other particulate collection systems.
The various radiation detection systems used throughout steelmaking and other production facilities were typically checked and tested periodically to insure continued operation and detection capability. The processes and procedures used to test the detection systems usually involve presenting a known radiation source to the radiation detector and verifying that an alarm or alert was generated. These testing methods demonstrated functionality at the time of the test, but may not identify other problems with the radiation detection systems during operation. The operating status of the radiation detection systems was not often known between testing intervals presenting the possibility for radioactive material to enter and be processed in the production facility during times when a radiation detection system was partially or whole inoperative.
There has been a need for a centralized radiation safety officer (CRSO) to monitor all of the production facilities in a network of faculties. The centralized radiation detection system would provide standardized radiation detection at all points within a production facility and provide standardized radiation detection at a number of different production facilities that may be located at widely dispersed geographic locations. It was also needed that the centralized radiation detection system would be able to permit a CRSO to coordinate with an LRSO to provide and maintain substantially uniformly radiation detection. There was also a need to be able to centrally review the radiation detection data from all production facilities in a network to identify recurring sources from which radioactive scrap or other recycled material has been originating for remediation. It was also desired that the radiation system can be expanded to detection of radioactive scrap by scrap or recycle dealers prior to shipment to the production facility.
Further, the radiation detection system may be substantially improved by the CRSO being an independent company that provides insurance to the operator of the production facilities to mitigate losses associated with contamination by radioactive material going undetected in the production facility. This provides the CRSO with incentive and motivation to maintain the same safe level of detection of radioactive material throughout the production facilities in a network.
A central system of monitoring radiation levels in a plurality of facilities at the same time is presently disclosed. The system may comprise a plurality of radiation detection systems capable of detecting radiation levels in recycled material positioned at a plurality of locations through a network of facilities, at least one processor to process monitoring data generated by each radiation detection system to compensate for naturally occurring radiation, a central monitoring station capable of receiving data from the processor and identifying radioactive material in the recycled material at each radiation detection system, and the central monitoring station capable of generating an alarm at the central monitoring station and at the facility involved where an undesired radiation level has been recorded by at least one radiation detection system.
A central system of monitoring radiation levels in a plurality of steelmaking facilities at the same time is also disclosed comprising a plurality of radiation detection systems capable of detecting radiation levels in scrap loads positioned at a plurality of locations through a network of steelmaking facilities, at least one processor to process monitoring data generated by each radiation detection system to compensate for naturally created radiation, a central monitoring station capable of receiving data from the processor identifying radioactive material in scrap loads at each radiation detection system, and the central monitoring station capable of triggering an alarm both at the central monitoring station and at the steelmaking facility involved where an undesired radiation level has been recorded by at least one radiation detection system. The processor identifying radioactive material in the scrap load may be located as part of each location detection system, at a central or segmented servers in the steelmaking facilities, or as part of the central monitoring station.
A system of monitoring radiation levels in multiple steelmaking facilities is also disclosed comprising a plurality of radiation detection systems positioned at a plurality of locations through a plurality of steelmaking facilities capable of detecting radiation levels of potential low-level radiation sources in steelmaking material, a central monitoring station in communication with the plurality of radiation detection systems capable of receiving data from the radiation detection systems corresponding to radiation levels, and the radiation detection systems capable of triggering an alarm both at the central monitoring station and at the steelmaking facility where an undesired radiation level as been recorded by at least one of the radiation detection systems.
A method of monitoring radiation levels in production facilities is also disclosed that includes detecting radiation levels in recycled material at desired locations through a plurality of production facilities by a plurality of radiation detection systems, communicating data corresponding to detected radiation levels from the radiation detection systems to a central monitor, analyzing the data from the radiation detection systems to determine the nature of a potential radiation source, disposing of material containing potential radiation sources according to instructions provided from the central monitor based upon the analysis of the data communicated from the radiation detection systems. The method may also include monitoring the operation of the plurality of radiation detection systems from the central monitor and signaling the facility when a radiation detection system requires maintenance.
The method of monitoring radiation levels in production facilities may also include calculating a probability that a potential radiation source will escape detection and contaminate a production facility, calculating an estimated cost for remediation of a contaminated production facility, and providing an insurance policy to compensate the production facility for at least a portion of the cost of remediation.
A method of monitoring radiation levels in steelmaking facilities may comprise a plurality of radiation detection systems capable of detecting radiation levels in steelmaking material positioned at desired locations through a plurality of steelmaking facilities, providing a central monitor in communication with the plurality of radiation detection systems, analyzing the data from the radiation detection systems to determine the nature of a potential radiation source in the steelmaking material, communicating data from the radiation detection systems to the central monitor corresponding to detected radiation levels, disposing of the steelmaking material containing potential radiation sources according to instructions provided from the central monitor based upon the analysis of the data from the radiation detection systems, and monitoring the operation of the plurality of radiation detection systems from the central monitor and signaling the facility when a radiation detection system requires maintenance.